Experts have raised concerns about the "disappointing" rate at which Victorians are getting their booster COVID-19 vaccine doses, as the possibility of a fourth dose is considered.
More than 93.7 per cent of eligible Victorians have had two doses of the vaccine, but the latest figures from the health department show 64 per cent of people aged 18 and up have now received three vaccine doses.
That figure has risen by less than seven percentage points in a month — it stood at 57.1 per cent on February 23.
The head of the University of Melbourne's School of Population and Global Health, Nancy Baxter, said the rate of booster vaccination was proving stubbornly slow.
"It's kind of disappointing that it's hovered around that two-thirds for some time now," she said.
Professor Baxter said the rate was concerning given COVID-19 cases were again starting to rise.
"Those people face significant risks, so we really need to get that booster number up," she said.
"We know our immunity from vaccination does decline over time, more so for getting the virus than for getting seriously ill from the virus.
"The booster brings that back up to the way it was before our immunity declined."
ATAGI is expected to release advice soon on whether Australians should get a fourth dose of the vaccine.
It is currently only available for severely immunocompromised people, but Professor Baxter said that is likely to change.
"It's just a matter of when we get that fourth dose."
Socio-economic status 'main factor' in booster uptake
Victorian government data showed the discrepancies in booster uptake between local government areas.
Areas experiencing socio-economic disadvantage such as Hume, Dandenong and Brimbank, had some of the lowest booster rates in the state.
The tiny LGA of Queenscliffe, on the other hand, had almost universal booster uptake.
It is one of the highest ranked LGAs in the state for socio-economic advantage, with an older population that has been eligible for the vaccine longer and is more vulnerable to COVID.
John Glover, director of the public health information development unit at Torrens University, said socio-economic factors such as income, occupation, employment, Aboriginal and Torres Strait Islander status and English as a second language play a big role in vaccination rates.
"Socio-economic status is the main factor influencing the variation in the take up of the booster — of the third dose."
He said the disparity has closed over time, owing to governments supporting outreach programs for communities experiencing socio-economic disadvantage.
"That's really the only way to improve the booster vaccination rates — to work with the local communities, the Aboriginal communities, the non-English speaking communities, and other disadvantaged groups.
Victorian government data showed the age group with the highest booster rate was those aged 70 and up, at 86.6 per cent.
Meanwhile, only 42.1 per cent of Victorians aged 18 to 29 had received three doses — the lowest rate for the adult population.
Professor Glover said people might be motivated to get their boosters as the BA.2 variant continues to spread throughout Victoria and cases rise.
'It's time to do it'
As the Royal Exhibition Building vaccination hub wound up its work on Wednesday, some took a last minute trip to the centre in Carlton to get their booster shots.
Nicole Hodge has been eligible for a booster COVID-19 vaccine for months, but she only got around to getting the jab on Friday.
"I was doing something in my life and went 'oh, we'll put it off just in case I had a reaction to it', but it's time to do it," she said.
"If I have a side effect and get a bit coughy or feverish then I can't do things on the weekend, so I need to make sure it's a quiet time in my life."
The 32-year-old also said her fears about catching the virus had declined over the course of the pandemic.
"I feel pretty safe with the double [dose] and this is more of a precaution. I stay at home, I work from home, so I don't feel as worried about getting COVID nowadays as I used to."
Clayton Young, 25, said he always intended to get his booster shot, but circumstances got in the way.
"I got COVID and then I didn't want to get [the vaccine] straight after because I wanted it to be more effective so I waited a few months and then I had a few events on," he said.
"I had the natural immunity from getting COVID so I wasn't as worried about it."
Liz Martin lives in Bendigo but travelled to the Royal Exhibition Building to get her dose of the Novavax vaccine.
Ms Martin said her doctor recommended Novavax for medical reasons, but she could not get it in Bendigo.
"It's been difficult because I could've had it two months ago but I've been waiting to get it in Bendigo since ATAGI approved it as a booster, but yeah, I've had to wait all this time and now I've had to drive to Melbourne, which is just absurd," she said.